Of late, the concept of trusted computing hardware has become more important. Trusted computing often involves placing a piece of trusted hardware within a computer. Examples of such trusted hardware include the trusted platform module (TPM), for which the specifications have been defined by the Trusted Computing Group (TCG) consortium. Trusted hardware often includes tamper-resistant hardware. If someone attempts to use the hardware in a way other than how it was designed, for example, by attempting to disassemble the hardware, the trusted hardware becomes unusable.
Trusted hardware's use in computers helps to provide a measure of certainty about the identity of the computer. But how much the computer can be trusted, or even if the computer can be trusted at all, is a separate issue. For example, even though a computer might include trusted hardware, the presence of the trusted hardware does not provide any protection against a virus, which might then be spread to another computer.
Routers, as compared with general-purpose computers, tend to be specialized devices. A router is responsible for directing traffic around a network. The router receives data, usually in packets, and uses information in the packets to determine where the data came from, and to where the data is supposed to be directed. Sometimes the router is connected to the destination of the data; sometimes the router needs to select another router in the network to deliver the data, in the hopes that the other router is closer to the data destination. But trusted hardware, which meets a particular need for general purpose computers, have not yet found their way into routers. As yet, there is no way to determine the integrity of a router, or to use such information in the normal operation of a router.
Accordingly, a need remains for a way to determine the integrity of a router and to use that information in routing data, to address these and other problems associated with the prior art.